1. Field of the Invention
The present invention relates to a liquid crystal display apparatus, a method for controlling the same, and an image display system.
2. Description of the Related Art
In recent years, LED (Light Emitting Diode) is progressively adopted as the backlight light source for the liquid crystal panel. The backlight, in which LED is used, includes the direct type LED backlight provided with LED arranged on the back surface of the liquid crystal panel. The direct type LED backlight has such a feature that the light emission luminance of the backlight can be changed locally. The backlight control system, which makes use of such a feature, includes a technique called “local dimming” in which the light emission luminance of the backlight is controlled for each of light source blocks depending on an input image signal. In the local dimming, the light emission luminance of the backlight is adjusted for each of the light source blocks, and hence it is possible to expect the effect to improve the contrast as compared with a case in which the light emission luminance of the entire surface of the backlight is adjusted.
A technique described in Japanese Patent Application Laid-open No. 2008-164863 is known as a conventional technique in relation to the local dimming as described above. In this conventional technique, a light source, which is divided into a plurality of light source blocks to be controlled, is provided, and the respective luminance values of the plurality of light source blocks of the light source are calculated from input image data corresponding to the plurality of light source blocks. The conventional technique discloses a transmission type display apparatus based on the use of a backlight in which the lighting of the light source is controlled on the basis of the calculation result.
On the other hand, the realization of high resolution of the display is advanced. It is predicted that a user, who photographs still images, may display the still image as the product or work of the user himself/herself on a high resolution display, and the user may utilize the high resolution display as a field of expression in future. In such a situation, it is necessary for the user to perform the image quality adjustment for the product or work (still image) of the user himself/herself in combination with a specified display. Further, in the case of a display in which the local dimming control is performed, it is necessary to perform the image editing (for example, change of layout, trimming, enlargement, and contraction) while considering the effect to improve the contrast to be brought about by the local dimming.